antoine lavoisier periodic table

There are seven periods in the periodic table and each period starts with a different principal quantum number. The first period corresponding to 'n' = 1 consists of only two elements hydrogen (1s 1 ) and helium (1s 2 ). This is because the first e..

With developments on the structure of atoms, it was discovered that the atomic number (Z) is the important characteristic of the atom and not the atomic mass. This led to the development of the modern periodic law by Moseley in 1942. The modern periodic law states that "the phys..

Introduction - With the rapid development of Chemistry and the discovery of new elements, it was necessary to develop a simple way to study and remember the numerous properties of the elements and their compounds. This gave rise to the necessity of classification of the elements into various groups..

Mendeleev's periodic table was one of the greatest achievements in chemistry with some of its important contributions as follow..

Mendeleev's Periodic Table - In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties by giving a law known as the periodic law. The name periodic law stems from the fact that the properties of the elemen..

In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties by giving a law known as the periodic law. The name periodic law stems from the fact that the properties of the elements orderly recur in a cyclic fashion. His pe..

Main Features of Modern Periodic Table - 1. The modern periodic table is divided into two main categories: (i) Vertical columns called Groups and (ii) Horizontal columns called Periods. 2. There are 18 vertical columns or groups. These are further s..

In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties by giving a law known as the periodic law. The name periodic law stems from the fact that the properties of the elements orderly recur in a cyclic fashion. His h..

The position of an element in the periodic table is generally determined by its electronic configuration e.g. electronic configuration of sodium is 2, 8, 1 i.e., it has three shells and one electron in the outermost shell. Hence, it is placed in period number 3 and gro..

Mendeleev's Periodic Table - In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties in the increasing order of the atomic masses, in the form of a table. Mendeleev had observed that properties of the elements ord..